1. OMG Issue

RLS11 — CRS definition for pose information

  • Key: RLS11-15
  • Legacy Issue Number: 16184
  • Status: closed  
  • Source: JARA ( Shuichi Nishio)
  • Summary:

    Explicit CRS definition for pose information is necessary. Especially, the relation between pose CRS and position CRS and its semantics shall be defined

  • Reported: RLS 1.0 — Sun, 8 May 2011 04:00 GMT
  • Disposition: Resolved — RLS 1.1
  • Disposition Summary:

    In ISO 19111 which RLS is based on, relation between CRSs is defined by using
    datums and transformations. In this sense, in order to represent pose information,
    we need to define a new datum. However, we found that generally this is not
    appropriate as identifying pose is tightly related to its associated position. In the
    original idea of CSs and CRSs in ISO 19111, CSs implicitly hold transformations
    that can in most cases be identified trivially. However, when extending this to
    pose, the necessary transformation becomes not so trivial and thus a much
    explicit mean for specifying the associated transformation, in combination with
    ‘position’ transformation, becomes necessary. Moreover, it is only a special case
    that position and pose information (or transformations) are mathematically
    independent, i.e., where transformations for position and pose can be defined
    separately. Therefore, position and pose information shall be represented in
    combination inseparable from each other. One way is to represent position/pose
    as a generalized position which is a set of parameters for a transformation that
    defines a mapping from the base CRS to the resulting position/pose. In this
    sense, what is called a CS or CRS shall be represented as a transformation ,and
    coordinate values which we normally call ‘position’ are parameters for the
    transformation. (for detailed discussion, see [Noda2010])
    [Noda2010] Itsuki Noda, Shuichi Nishio, Takashi Tsubouchi, Takeshi
    Sakamoto and Satoshi Tadokoro, "Mathematical Framework for Localization
    Information Coordinate Reference System for Robotics", in Proc. of Int.
    Workshop on Standards and Common Platform for Robotics 2010 (SCPR
    2010), 2010.
    This notion is mathematically much rigid. However, it requires complete
    reconstruction of the ISO 19111 which RLS is based on. As this is not something
    to be discussed here, here we propose a much modest modifications. In the
    future, this shall be discussed in ISO/TC 211.
    Followings are the modified points: - Add non-normative reference

    • Add background description (section 7.3 – Architecture Package)
    • Add two classes (PoseType and PositionPoseCRS) in Architecture Package
    • Define frequently used pose types
    • Modify section 7.4.1 – Common Data Format to use the defined pose types and
      remove figures/descriptions that also appear in previous description
    • Modify C++ PSM accordingly
  • Updated: Fri, 6 Mar 2015 20:58 GMT